Method and apparatus for compressively crimping textile strands

ABSTRACT

Textile strands are compressively crimped by propelling them lengthwise, as by a fluid jet, into buckling contact with a smooth solid surface. The crimped strand accumulates on an adjacent moving screen, which preferably has a cylindrical strand-supporting surface. Rotation of the screen aids in collection and retention of the crimped strand until it is withdrawn therefrom at the leading edge of the strand accumulation after about half a revolution.

United States Patent [1 1 Stanley 1 51 Jan. 1, 1974 METHOD AND APPARATUS FOR COMPRESSIVELY CRIMPING TEXTILE STRANDS [75] Inventor: Robert K. Stanley, Media, Pa.

[73] Assignee: Textured Yarn Co., Inc., Kennett Square, Pa.

[22] Filed: Aug. 30, 1971 [2]] Appl. No.2 176,029

[52] U.S. Cl 28/1.6, 28/7214, 226/118 [51] Int. Cl D02g 1/12 [58] Field of Search 28/].4, 1.6, 72.12,

[56] References Cited UNITED STATES PATENTS 1,732,526 10/1929 Mumford 57/77 1,779,313 10/1930 Hegan eta1.... 57/76 X 1,988,490 1/1935 Harrison 57/77 1,990,617 2/1935 Sanders et al. 57/76 X 2,042,529 6/1936 Huttlnger 57/76 X 2,198,962 4/1940 Eisenhut et a1. 28/].6 UX 2,435,891 2/1948 Lodge 28/7212 X 2,753,706 7/1956 Franklin 226/118 X 3,064,328 11/1962 McClure et a1.... 28/21 3,143,784 8/1964 Scott 28/7212 Primary Examiner-Robert R. Mackey Att0rneyMcC1ure & Millman [57] ABSTRACT Textile strands are compressively crimped by prop'elling them lengthwise, as by a fluid jet, into buckling contact with a smooth solid surface. The crimped strand accumulates on an adjacent moving screen, which preferably has a cylindrical strand-supporting surface. Rotation of the screen aids in collection and retention of the crimped strand until it is withdrawn therefrom at the leading edge of the strand accumulation after about half a revolution.

16 Claims, 8 Drawing Figures METHOD AND APPARATUS FOR COMPRESSIVELY CRIMPING TEXTILE STRANDS This invention relates to the compressive crimping of textile strands, as by propelling such a strand lengthwise into buckling contact against a flat or smooth surface and accumulating it in resulting crimped configuration on an adjacent foraminous strand-supporting surface.

In conventional techniques for compressive crimping of textile strands such a strand to be crimped usually is forced lengthwise into one end of a tubular enclosure by feed rolls, although sometimes by fluid transport, to buckle as it then comes into contact with an accumulation of the same strand previously forced thereinto, after which the crimped strand is withdrawn from the leading edge of the strand accumulation by being wound up out of the opposite end of the enclosure. Such technique suffers from throughput limitations, and the parts of the strand that slide along the enclosure wall often exhibit different physical characteristics, such as a noticeable dyeability differential, as compared with the rest of the crimped strand. It is also known to propel strands against a foraminous barrier or screen to compress them longitudinally, but such impact is deleterious to strand components, being conducive to breaking thereof. Also, openings in such screens or barriers tend to snag fine filaments or fibrils and to fill up with fibrous and particulate matter.

A primary object of the present invention is enhanced uniformity of treatment in compressive crimping of textile strands.

Another object is compressive crimping of textile strands so as to reduce physical degradation thereof attributable to propulsion, impact, or other handling.

A further object is high-speed compressive crimping of textile strands applicable to strands comprising relatively narrow ribbons, strips, or tapes, whether prefibrillated or not, as well as to strands comprising one or more filaments.

Other objects of the invention, together with means and methods for attaining the various objects, will be apparent from the following description and the accompanying diagrams.

FIG. 1 is a front elevation, partly diagrammatic, of apparatus according to the present invention;

FIG. 2 is a plan view through an apparatus compo nent of FIG. 1 (with strand therein);

FIG. 3 is a fragmentary sectional elevation of the same apparatus component, taken at line IIIIII on the last preceding view;

FIG. 4 is a side sectional elevation of the same apparatus component, taken at line IV-IV on FIG. 1;

FIG. 5 is a bottom perspective view of an auxiliary apparatus component;

FIG. 6 is a sectional elevation through part of the component of FIG. 5 in operating juxtaposition to the apparatus of preceding views;

FIG. 7 is an end elevation of additional auxiliary apparatus components in operating position; and

FIG. 8 is a plan view of the apparatus of FIG. 7.

In general, the objects of the present invention are accomplished, in lengthwise compressive crimping treatment of textile strands to impart a crimped configuration thereto, by propelling a crimpable textile strand as by a propulsion fluid, continuously against substantially flat (smooth) means and thereby forming it into crimped configuration, accumulating the crimped strand on adjacent foraminous strand-supporting means, and continuously removing crimped strand therefrom at the leading edge of the so supported accumulation. The foraminous means is preferably curved and adapted to rotate about its center of curvature to aid in collecting and retaining the strand accumulation thereon.

FIG. 1 shows, partly in elevation and partly schematically, a frame of apparatus useful according to this invention, supporting various components and with strand 11 being treated thereby. The strand is withdrawn from package 12 thereof on a support at one end of the frame. The strand passes in sequence through guide 13, around idler roll 14, and through the successive nips of metering rolls 17, 17' and 18,18. Rolls 17 and 18 are driven by belts 7 and 8 from pulleys (not shown) on shaft 9 ofa motor 10. From the final roll nip the strand passes via guide 19 to a branch inlet of jet 20. The jet is supplied thorugh a main inlet with propulsion fluid, as by pump 5, by way of interconnecting rigid and flexible lines designated generally as 6 and provided with pressure gauge 4. Fluid enters the main inlet tube and propels strand 11 from the branch inlet tube through the junction of the inlet tubes and out the outlet end. As shown in more detail in subsequent views, the exiting strand impinges forcibly against the flat lower surface of shallow cylindrical means 30, which is open centrally at the top and which has a foraminous cylindrical surface.

FIGS. 2 and 4 show cylindrical means 30 enlarged in scale as compared with FIG. 1 and in plan (partly cut away) and sectional elevation, respectively, and FIG. 3 shows a sectional detail thereof. Supported for rotation on vertical shaft 31, the cylindrical means comprises a shallow cylinder having flat impervious bottom wall 32 affixed to the shaft, cylindrical screen 33 joining the peripheral edge of the bottom wall and the peripheral edge of top wall 34, which has central opening 35 therein. The outlet tube ofjet 20 extends into the shallow cylinder through the central opening in the top wall and terminates under the edge of that top wall and about midway ofthe cylinder depth at a substantial angle (here about 45) to the flat lower wall and at an equivalent distance from screen 33, which forms the cylindrical wall. Crimped strand accumulation 11' (so designated to distinguish it from original strand 11) lies against the screen and between the adjoining portions of the top and bottom walls where it accumulates by reason of centrifugal force imparted to it by forcible crimping contact with the lower wall of the rotating cylinder.

As shown in FIG. 1, cylindrical means 30 is rotated on shaft 31 by bevel gearing 39 (only fragmentarily indicated) driven through belt 37 from a suitable drive pulley. Crimped strand 11" (so designated to distinguish it from accumulation 11' thereof in the rotating cylindrical means, as well as from the original strand) is withdrawn through central opening 35 in the top wall and passes about guide 41 and through stabilization chamber 40, which has entrance and exit openings to accommodate it. From the stabilization chamber it proceeds through guide 42, over windup roll 43, which may be slotted appropriately to traverse the strand, and onto package 44 carried on swing arm 45. The swing arm is biased from an alternative (shown in phantom) oblique position, useful for package removal, against stop 46 by weight 47 suspended on cable 48 passing over pulley 49 and secured to the top of the swing arm. The windup roll is driven by belt 3 from a similar drive pulley (not shown).

Operation of the described and illustrated apparatus to practice the process of this invention is readily understood. The strand is withdrawn from the package or other suitable source by the metering rolls and forwarded thereby to the fluid jet. Suitable propulsion fluid, such as air compressed from the atmosphere, propels the strand through the jet and against the flat impervious lower surface of the rotating cylindrical means, the fluid dissipating principally through the apertures in the adjacent screen. The forcible impact of the strand so propelled causes it to buckle into crimped configuration. The crimped strand accumulation lies against the concave interior surface of the rotating screen, where it is retained, at least in part by centrifugal force, in the channel formed by the flat top and bottom walls and the cylindrical screen.

Inasmuch as the jet is fixed in position and the screen is rotating continuously, the accumulating crimped strand does not pile up on itself but progresses along the screen counter to the direction of rotation. The locus of impact of the strand is always near the trailing edge of such accumulation, while the leading edge thereof is something over a half circle away, where crimped strand is withdrawn from the accumulation thereof. The windup roll withdraws the crimped strand out from under the overhanging top wall of the cylindrical means, the locus of withdrawal being determined by the ratio of withdrawal to rotational speed and the ratio of withdrawal speed to the speed at which the untreated strand is metered into the crimping zone, as well as by the crimping characteristics of the strand material and also the fluid pressure and the flow rate and volume.

The various speed ratios normally are maintained fixed, as suggested by the drive belts shown on a common drive pulley, but suitable provision for adjusting such ratios as may be desirable is readily available in the form of continuously variable drive linkages as well as stepwise variable pairs of pulleys, etc. Of course, the speed at which the strand issues from the outlet end of the jet is considerably greater than the rotational speed of the cylindrical means at the locus of impact of the issuing strand against the impervious flat lower wall thereof, such as at least twice and preferably several times as great. The crimping itself reduces the effective overall length of the strand by a minor fraction in the range of at least about one tenth but less than five tenths, usually between two and three tenths. The windup speed is accordingly less than the supply (or propulsion) speed. The residual excess of supply speed over screen speed causes the strand to accumulate in the illustrated serpentine folds along the screen.

FIG. 5 shows, in perspective, tension ring 51, which is a useful adjunct to cylindrical means 30 shown in the preceding views. The ring has flat annular portion 52 and depending cylindrical flange 53 along the inner edge thereof bounding central opening 54. The maximum radial dimension of the flat annular portion approximates that of top wall 34 of the cylindrical means, while the minimum radial dimension of that portion and of the depending flange is somewhat less than that of wall 34, whereupon the ring is adapted to rest upon that wall with the ring flange depending into central opening 35 in the top wall of cylindrical means 30 as shown in the next view.

FIG. 6 shows, in fragmentary sectional elevation, tension ring 51 in operating juxtaposition to cylindrical means 30 as just described. Crimped strand 11" is withdrawn over the inner edge of top wall 34, as previously shown, but now it passes in contact with the upper surface of that wall and with the lower surface of annular portion 52 of the tension ring resting thereon. This aids in reduction or removal of slubs or tangled portions of the strand and assures its presentation in orderly fashion to the withdrawal or windup means. No attempt is made in this view or succeeding views to depict the crimped configuration of the strand being withdrawn, which does not become fully apparent until it is released from the tension of withdrawal or winding.

FIG. 7 shows in elevation, and FIG. 8 in plan, auxiliary withdrawal means comprising pair of tapered rolls 61, 71 carried on their respective axles 62, 72 by suitable auxiliary frame means (not shown). Roll 61, preferably made of steel or similar metal, is drawn by appropriate drive means (also not shown) at desired withdrawal speed. Roll 71, preferably made of rubber or resilient plastic composition, is undriven. As shown, the rolls are contiguous, with their corresponding sizes of ends mutually adjacent, and are oriented on axes in a plane substantially parallel to top wall 34 of the cylindrical means.

As shown more clearly in FIG. 8, the axis of driven roll 61 is substantially parallel to a tangent to the wall at its nearest approach thereto. The roll taper opposes the direction of rotation so that crimped strand is withdrawn at a rapid rate over the larger roll surface thereof upon displacement of the leading edge of the strand accumulation in that direction. It will be apparent that, contrariwise, if the leading edge is not carried so far in the direction of rotation, the crimped strand is withdrawn at a lower rate over the smaller roll surface, thereby stabilizing the location of the leading edge.

When used with the further windup apparatus shown in FIG. 1, these tapered rolls would precede guide 41 or (if such guide is not used) the next succeeding element in the windup path. It will be understood that the rolls are not shown to scale and may be longer than the views suggest, may have a different taper, and may be provided with end guides to retain the strand on the rolls despite possible excessive speed variations or other unusual occurrence.

It will be understood that the strand to be treated, although perhaps most likely uncrimped, may have been crimped previously by any suitable method, whereupon the present treatment would superimpose a second crimp upon the first. For example, the strand may have been crimped previously by a twist (or false-twist) method and then be compressively crimped hereby, as suggested with illustration and description together with a conventional compressive or stuffer-crimping operation in my U.S. Pat. No. 2,972,798.

If of drawable composition, the strand often will have been drawn quite some time before being crimped. However, a drawing step may be performed immediately before crimping, as suggested with illustration and description of a conventional compressive or stuffercrimping operation in my U.S. Pat. No. 3,462,814, which lists many drawable strand compositions suited to draw-crimping operation. The strand may even be taken directly from extrusion to drawing and crimping,

as suggested with illustration and description of a conventional stuffer-crimping operation in my US. Pat. No. 3,499,953. Draw-crimping according to the present invention is readily accomplished by driving the second set of metering rolls (l8, 18) at a sufficiently higher surface speed than the first set (l7, 17'), as in a ratio of 4:1, for example.

Thermoplastic textile strands usually may be drawn or crimped (or both) more readily by heating thereof before or at the time of assuming drawn or crimped configuration, as indicated in my aforementioned patents. When draw-crimped, the strand preferably is not allowed to cool intermediately but is maintained at temperature conducive to crimping.

According to the present invention preheating to reach (or continued heating to maintain) a desired strand-treating temperature is readily accomplished. The propulsion fluid used in the jet may be hot air or steam, for example, so as to heat the strand passing therethrough. The strand may be heated similarly by an auxiliary hot fluid applied to the strand after contact with an unheated propulsion fluid. Radiant heating of the strand may be provided between the jet and the screen means. Such heating techniques are used especially according to this invention in the treatment of strands composed of relatively thermal-resistant materials, e.g., glass filaments.

Stabilization of the strand in its acquired configuration, as in the mentioned chamber, also customarily involves heat and may involve hot rolls, radiant heating, or treatment with hot fluid (which may be supplied from the same source as the propulsion fluid, if desired), moist or dry, and may involve tension application. See, for example, the heat-relaxation disclosed in w my US. Pat. No. 3,221,385, and as augmented by a cooling aftertreatment in my US. Pat. No. 3,561,082. Selection of suitable heating means, whether for pretreatment or posttreatment (or both), is well within the ability of persons ordinarily skilled in the art, and no such heating means is illustrated or further described here.

The present invention is adapted to operation at high speeds, such as upwards of a thousand yards or meters per minute. Such speeds are more readily attainable than in conventional stuffer-box types of compressive crimping because of the readier entry and exit of the strand from the open'sided channel-shaped chamber disclosed here than possible in the more complete enclosure customarily employed. The resulting crimp level is very even, and no undesirable crimp diminution occurs during windup, which is readily accomplished at relatively low tension.

Although a specific embodiment of the invention has been illustrated and described, certain modifications have been suggested hereinabove. Additional modifications, such as addition, combination, or subdivision of parts or steps, or substitution-of equivalents, may be made while retaining all or some of the advantages and benefits of the invention, which itself is defined in the following claims.

I claim':

1. ln strand-crimping means, a cylindrical strandreceiving chamber comprising a foraminous cylindrical wall and a pair of relatively flat walls parallel to one another and perpendicular to and flanking the foraminous cylindrical wall, one of the walls having a central opening therethrough, means for propelling a strand to be crimped into the chamber through the opening and into buckling contact with the inside of one of the flat walls at a rate sufficient to accumulate temporarily therein and be supported thereby in crimped condition, means for rotating the chamber about the cylinder axis, and withdrawal means for removing crimped strand therefrom.

2. Strand-crimping apparatus according to claim 1, wherein the chamber is open also in the centripetal direction.

3. Strand-crimping apparatus according to claim 1, wherein the strand-withdrawal means is located on the opposite side of the axis relative to the strandpropelling means.

4. Strand-crimping apparatus according to claim 3, wherein the withdrawal means comprises variablespeed components providing a graduation in withdrawal speed in direct relation to the extent of rotation of the strand accumulation on the supporting screen.

5. Strand-supporting apparatus according to claim 4, wherein the withdrawal means comprises a pair of nip rolls having conical configuration, arranged with their nip substantially tangential to the direction of rotation and their taper from small to large in that direction.

6. Apparatus for crimping textile strands by lengthwise compression thereof, comprising a rotatable hollow cylinder having a foraminous cylindrical surface and flat end surfaces, with a central opening in one of the ends, a fixed strand-forwarding jet terminating obliquely relative to the flat surface of the other of the ends inside the-cylinder and adapted to forward strand from the exterior of the cylinder through the central opening to impinge forcibly against such flat surface and thereby be buckled into crimped configuration, means for rotating the cylinder about its axis such that the crimped strand is temporarily accumulated and supported against the concave side of the foraminous cylindrical surface, and strand-withdrawal means located on the opposite side of the axis from the jet and effective to remove strand from the accumulation thereof after substantially half a turn of rotation of the cylinder from the impingement location.

7. Strand-crimping apparatus according to claim 6, including means for preheating the strand in advance of the locus of contact with the cylinder.

8. Strand-crimping apparatus according to claim 6, including means for postheating the strand after withdrawal from the cylinder.

9. Strand-crimping treatment comprising propelling a textile strand forcibly into buckling contact with a smooth solid surface at such a rate as to accumulate temporarily thereadjacent in buckled condition, supporting the strand at least partially on an adjacent cylindrical screen rotating relative to the locus of contact, and withdrawing the strand continuously therefrom, wherein the strand accumulation is left unconfined in the centripetal direction.

10. Strand crimping according to claim 9, wherein the rotation is effected about a vertical axis, and the crimped strand accumulation is confined both above and below while supported on the screen.

11. Strand crimping according to claim 10, wherein crimped strand is removed from the accumulation thereof on the rotating screen after being supported thereon throughout about a half circle of rotation thereof.

the crimped configuration of the strand is enhanced by so treating the strand while hot.

14. Strand crimping according to claim 12, including the step of preheating the strand just before it impinges against the flat moving surface.

15. Strand crimping according to claim 12, including the step of postheating the strand after withdrawal thereof.

16. Strand crimping according to claim 12, including heating the strand by application of hot fluid thereto before withdrawal thereof. 

1. Strand-crimping treatment comprising propelling a textile strand forcibly into buckling contact with a smooth solid surface at such a rate as to accumulate temporarily thereadjacent in buckled condition, supporting the strand at least partially on an adjacent cylindrical screen rotating relative to the locus of contact, and withdrawing the strand continuously therefrom, wherein the strand accumulation is left unconfined in the centripetal direction.
 2. Strand crimping according to claim 1, wherein the rotation is effected about a vertical axis, and the crimped strand accumulation is confined both above and below while supported on the screen.
 3. Strand crimping according to claim 2, wherein crimped strand is removed from the accumulation thereof on the rotating screen after being supported thereon throughout about a half circle of rotation thereof.
 4. In lengthwise compressive treatment of textile strands to impart a crimped configuration thereto, the improvement comprising propelling a crimpable textile strand lengthwise continuously at an essentially fixed location obliquely against an essentially flat solid surface moving in its own plane, to buckle into crimped configuration, accumulating the crimped strand temporarily supported centrifugally but inconfined centripetally on an adjacent foraminous cylindrical surface rotating about its axis, and continuously remOving crimped strand at the leading edge of the temporarily supported strand accumulation thereon.
 5. Strand crimping according to claim 4, wherein the crimped configuration of the strand is enhanced by so treating the strand while hot.
 6. Strand crimping according to claim 4, including the step of preheating the strand just before it impinges against the flat moving surface.
 7. Strand crimping according to claim 4, including the step of postheating the strand after withdrawal thereof.
 8. Strand crimping according to claim 4, including heating the strand by application of hot fluid thereto before withdrawal thereof.
 9. In strand-crimping means, a cylindrical strand-receiving chamber comprising a foraminous cylindrical wall and a pair of relatively flat walls parallel to one another and perpendicular to and flanking the foraminous cylindrical wall, one of the walls having a central opening therethrough, means for propelling strand to be crimped into the chamber through the opening and into buckling contact with the inside of one of the flat walls at a rate sufficient to accumulate temporarily therein and be supported thereby in crimped condition, means for rotating the chamber about the cylinder axis, and withdrawal means for removing crimped strand therefrom.
 10. Strand-crimping apparatus according to claim 9, wherein the chamber is open also in the centripetal direction.
 11. Strand-crimping apparatus according to claim 9 wherein the strand-withdrawal means is located on the opposite side of the axis relative to the strand-propelling means.
 12. Strand-crimping apparatus according to claim 11, wherein the withdrawal means comprises variable-speed components providing a graduation in withdrawal speed in direct relation to the extent of rotation of the strand accumulation on the supporting screen.
 13. Strand-supporting apparatus according to claim 12, wherein the withdrawal means comprises a pair of nip rolls having conical configuration, arranged with their nip substantially tangential to the direction of rotation and their taper from small to large in that direction.
 14. Apparatus for crimping textile strands by lengthwise compression thereof, comprising a rotatable hollow cylinder having a foraminous cylindrical surface and flat end surfaces, with a central opening in one of the ends, a fixed strand-forwarding jet terminating obliquely relative to the flat surface of the other of the ends inside the cylinder and adapted to forward strand from the exterior of the cylinder through the central opening to impinge forcibly against such flat surface and thereby be buckled into crimped configuration, means for rotating the cylinder about its axis such that the crimped strand is temporarily accumulated and supported against the concave side of the foraminous cylindrical surface, and strand-withdrawal means located on the opposite side of the axis from the jet and effective to remove strand from the accumulation thereof after substantially half a turn of rotation of the cylinder from the impingement location.
 15. Strand-crimping apparatus according to claim 14, including means for preheating the strand in advance of the locus of contact with the cylinder.
 16. Strand-crimping apparatus according to claim 14, including means for postheating the strand after withdrawal from the cylinder. 